Automobile headliners typically are laminated of rigid foam or mat-like support base layer, an intermediate soft foam layer and a decorative cover layer. This laminate is molded to fit the contour of the interior of a vehicle roof. The headliner is preferably supported on each side of the roof by molding strips and by a dome light fixture if present.
Frequently the base layer is molded from a resin bonded fiberglass mat because of its low cost and superior sound deadening properties. Such fiberglass headliners are typically made by coating the surface of a very large number of individual glass fibers with a suitable thermosettable resin, mixing the fibers into a loose mat form supported between two layers of scrim material and compression molding the mat in a matched tool under predetermined temperature and pressure to form a panel. Unlike a paperboard base layer or a styrofoam base layer, a fiberglass base layer molded by this process may have cross sections of variable thicknesses to fit the specfic contour of a vehicle roof desired. A decorative cover can be applied to such compression-formed panel by adhesive or other means.
Resin bonded fiberglass headliner panels are very flexible. In addition to the usual edge attachment, they have required other attachments to the vehicle roof, such as hook and loop type fasteners or structural adhesives to prevent fluttering of the headliner under driving conditions. These extra attachments are costly.
Transverse sheet metal reinforcing strips have been inserted into the fiberglass panel during molding to make it self-supporting. This has been disclosed in published German application DE No. 3208804-A by Muller. However, the metal strips add weight to the headliner, require labor for the installation and reduce sound deadening properties.